Refrigerating apparatus



March 28, 1939. J SMlTH 2,151,995

REFRIGERATING APPARATUS Filed March 29, 1935 3 Sheets-Sheet l INVENTOR.

/Vz I0 I SMITH BY ATTORNEYS March 28, 1939. N. J. SMITH REFRIGERATING APPARATUS Filed March 29, 1935 3 Sheets-Sheet 2 aw aw m T A E V m ATTORNEYS March 28, 1939. N. JISMITH 2,151,995

I REFRIG ERATING APPARATUS Filed March 29, 1935 s Sheets-Sheet s INVENTOR.

ATTORNEY.

Patent ed Mar. 28, 1 939 PATENT OFFICE 2,151,995 REFRIGERATING APPARATUS Nelson J. Smith, Dayton. Ohio, assignor to General Motors Corporation, Dayton, Ohio, a corporation of Delaware Application March 29,

3 Claims.

This invention relates to refrigerating apparatus and more particularly to a refrigerating apparatus adapted to provide conditioned air within an enclosure.

It is an object of this invention to provide a unitary structure which may be located within a space to be air conditioned and which will perform the functions of cooling, dehumidifying, cleaning and circulating the air within the en- I) closure in warm weather and will perform the functions of heating, humidifying, cleaning and circulating air Within an enclosure in cold weather, and in addition will provide for the introduction of selectively variable amounts of fresh air 5 to the enclosure in either warm or cold weather. Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

In the drawings: Fig. 1 is a vertical cross section of a refrigerating apparatus embodying the present invention;

Fig. 2 is a cross section on line 2-2 of Fig. l Fig. 3 is an end view of the device illustrated in Fig. 1, a portion of the apparatus being broken away; and i Fig. 4 is a diagrammatic view showing the connections of the essential elements of theappa- 30 ratus. I g

The device illustrated in Figs. 1 to 3 comprises generally a rectangular casing enclosing a refrigerant liquefying unit generally'designated as In, and an air treating unit generally designated 5 as l2. Both units are mounted upon a generally rectangular frame l4 within a casing I6. The unit is adapted to be supported upon the floor of an enclosure to beair conditioned and adjacent one of the side walls thereof, preferably near a 40 window.

The refrigerant liquefying unit II! is enclosed within an insulated chamber l8 havinginsulating walls 20 surrounding the same to prevent the con- 'duction of both heat and noise from the compartment I8 to the enclosure to beair conditioned. The refrigerant liquefying unit is mounted upon a frame 22 supported upon the main frame l4 and includes a motor 24, a compressor 26, a condenser 28, receiver 30 and a heat exchanger 32 for 0 cooling thegcompartment l8. The compressor26 is driven by the motor 24 through pulleys 34 and 36 and belts 38-. A fan 40 located on the motor shaft circulates the air within the compartment l8 over the heat exchange device 32.

The air treating unit l2 comprises a duct 4| 1935, Serial No. 13,710 (o1. est-s) for air to be treated formed by the walls of the casing I6, the wall 52 (see Fig. 2) and the common wall 39 between the units l0 and I2. The air treating duct 4| has two inlets, one of which is formed by the grille 42 for the ingress of re- 5 circulated air from the enclosure to be air conditioned and the other of which is situated at the window 44. A sheet metal elbow 46 is positioned in the top of the casing |6 at the rear thereof and may be vertically adjusted to correspond to the height of the sill of the window 44.. The rearwardly facing opening of the elbow 46 carries an adjustable sleeve 48 which is movable toward and away from the rear face ofthe unit so that it may be brought in contact with the window 44. A pad 50 of felt is secured to the sleeve 48 to insure air tight contact between the sleeve 48 and the sash of the window 44. The downwardly facing opening of the elbow 46 communicates with a duct 41 formed between the rear wall of the casing 6 and an intermediate sheet metal wall 52 which terminates in an opening 54 leading into the air treating duct 4| A replaceable filter screen 56 of any suitable construction is positioned diagonally in the duct 41 between the sleeve 46 and the opening 54. A drip pan 56 is positioned in the casing to form the bottom of the duct 4| and the top of the duct 58 which extends from the grille 42 to the opening 54 leading into the duct 4|. i Positioned in the duct 4| near the bottom there- .of is a refrigerant evaporator 60 of any suitable construction which is maintained at a low temperature by the refrigerant liquefying unit In. Above the evaporator 60, there is positioned a as heating coil 62 which is adapted to be connected with the heating system of the building within which the air conditioning unit is placed. Near the top of the duct 4| there is mounted an air circulating unit comprising a motor 64 which drives a pair of blowers 66 at either end thereof having their inlets 68 opening into the duct 4| and their outlets discharging through the top wall of the casing It. A humidifying device is also provided in the duct 4| comprising a control manifold 10 which is connected to a water distributing head I2 which overlies the heating coil At the right hand end of the device as viewed .in Fig. 1, a chamber 14 is provided within which are located the control devices for the air conditioning unit. The end wall of the casing i6 is provided with a control panel 16 (see Fig. 3) having located thereon all of the handles by which the various control devices are actuated. 'Ihus,v j

the knob 18 is connected by means of a lever and link connection to the temperature responsive element 82 positioned within the duct 58 which controls the admission of heating fluid to the coil 62 through the valve 84. The knob 86 which is reciprocable in a slot 88 controls through the medium of a link a damper 92 which is adapted to swing in the opening 54. The electrical controls for the apparatus are mounted within the casings 84 and 86 and are controlled through the medium of knobs 98, I00, I02 and I04 in a manner later to be described.

Referring now to Fig. 4 wherein the elements of the apparatus are illustrated diagrammatically, it will be seen that the evaporating coil 60 has its inlet end connected to the receiver 30 through a solenoid valve I06 and a thermostatic expansion valve I08 while its outlet end is connected to the crank case of the compressor 26 by means of a conduit H0. The heat exchanger 32, the manifold 10 and the condenser 28 are connected to a conduit II2 having a shut-off valve II4 therein which leads from a suitable water supply. The outlet of the condenser 28 and an outlet H6 formed in the drain pan 56 are connected to a suitable drain by conduits H8 and I20 respectively. The heating coil 62 is connected through the valve 84 to a conduit I22 and shut-01f valve I23 leading from a source of heating fluid such as steam or hot water while the outlet of the coil 62 is connected to the heating fluid return duct I24.

Control of the liquefying unit I0 is provided by means of the customary low pressure control switch I 26 which is mounted within the casing 84. The principal actuating bellows I28 of the switch I26 is connected by a conduit I30 to the suction line IIO while a high pressure cut-out bellows I32 is connected by means of a conduit I34 to the discharge side of the compressor. Suitable overload circuit breaking means (not shown) may be incorporated in the switch I26 and may be reset by the knob I04 shown in Fig. 3. A water control valve I36 is provided in the outlet conduit H8 and is controlled by head pressure through a conduit I 38 communicating with the discharge side of the compressor. The switch I26 is connected in series with the motor 24 by conductors I40, I42, and I44 leading from a suitable source of electric current.

The electrical control of the air treating unit I2 includes a thermostatic switch I46 located in casing 96 and having a temperature responsive element I48 positioned within the duct 58. The knob 98 is connected to the switch I46 in a manner to adjust the mechanism thereof to vary the temperature at which the switch responds. Switch I 46 is connected to the conductor I44 by a conductor I50 and is connected to the solenoid valve I06 by a conductor I52. The return line from the solenoid valve I06 includes the conductor I54, the on-ofl. switch I56 which is controlled by the knob I00, the conductor I58, the blower switch I60 which is controlled by the knob I02, and the conductor I62. The blower switch I60 has three positions, namely: ofl, high speed and low speed, reading downwardly in Fig. 4 and is provided with a conducting segment I64 by which a circuit is established between the conductors I58 and I62 in the high and low speed positions of switch I60. The motor 64 which drives the blowers 66 is connected to the conductor I50 by means of a conductor I66 and has its main winding also connected by means of a conductor I68 to the high speed position contact of the switch I60. The phase winding of the motor 64 is connected by means of a conductor I10 having a capacitator I12 connected in series therein with the low speed position contact of the switch I60. A resistor I14 is connected between the conductors I68 and I10. Thus, whenthrough the resistor I14. In the low speed position of the knob I02, the solenoid valve I 06 is in circuit as before, while the main winding of the motor 64 is connected to the conductor I62 through the resistor I14 and the phase winding has impressed thereon the full voltage of the current supply in series with the capacitor I12. It will thus be seen that the solenoid valve I 06 can be energized only when the motor 64 is en-- ergized for either high or low speed, thus preventing the delivery of refrigerant to the coil 60 whenever the motor 64 is turned 011'. The switch I 56 may be used to open the circuit of the solenoid valve I06 and thus cut oif refrigeration without the necessity of also turning off the blower motor 64.

Whenever the switch I56 is in the "on position and the switch I60 is in either the high or low speed position, the solenoid valve I06 is then subject to the control of the thermostatic switch I46 which acts to control'the delivery of liquid refrigerant to the coil 60 in accordance with the demand therefor as indicated by the temperature of the air flowing through the duct 58. The operation of the liquefying unit I0 is indirectly subject to control by thermostatic switch I 46 in the following manner. Whenever the switch I46 is open and the solenoid valve I06 is closed, the liquefying unit will run until the pressure within the evaporator 60 is reduced to the cut-out point of the switch I26. Thereafter the liquefying unit will remain idle until sometime after the switch I46 has again closed and the solenoid valve I06 has opened. It will be understood, of

course, that the control mechanism heretofore described exercises control only during such times as it is desired to cool the air within the space to be air conditioned, as during summer weather.

In winter weather, when it is necessary to heat the space to be conditioned, the switch I56 will be opened and the switch I 60 utilized solely as a control for the blower motor 64. Under these conditions, control of the heating of the air within the duct H is provided by the thermostatic valve 84 previously described. During both winter and summer conditions, the relation between the amount of recirculated air drawn in through the duct 58 and the amount of fresh air drawn in through the duct 41 may be varied by means of the knob 86 which controls the damper 82.

In operation of the unit as a whole under summer weather conditions, the compressor 26 is driven by the motor 24 to withdraw gaseous refrigerant from the evaporator 60 and to deliver compressed refrigerant to the condenser 28 where it is liquefied by the cooling water supplied through the conduit H2 and subsequently collected in the receiver 30. Whenever the solenoid valve I06 is open, liquid refrigerant is delivered LII to the expansion valve I where it is expanded into the evaporator 00 to reduce the temperature thereof in a well'known manner. The fan 40 circulates the air within the compartment I8 over the heat exchanger 32 to withdraw the heat of the motor and theheat of the compressor from the air in the compartment I0. The blowers 66v During winter operation, humidification of the air being conditioned is desirable and is provided by means of the water distributing head I2. The head 12 is divided into. three sections I16, I18 and I00, each of which is out of communication with the other except through the manifold 10'. Separate conduits I82, I84 and I86 lead from the manifold I0 to the separate portions of the head I2. Individual valves I00, I90 and I92 control the admission of water from the conduit 2 to the conduits I82, I84 and I86 respectively. Thus, if a small amount .of humidification is desired, only one of the valves in the manifold will be opened, thus delivering water to only onethird of the distributing head I2. The humidifying water is, therefore, distributed over only a small portion of the heating coil 62 and the amount of moisture added to the air passing to the conduit M is limited. If more humidification is desired, two or three of the valves in the manifold I0 may be opened, thus increasing the area on .the coil 62 over which humidifying water is distributed. It will be understood that very little control over the rate of humidification may be obtained by varying the amount of opening of any one of the valves in the manifold 10. This is due to the fact that substantially the smallest practical opening of any one of the valves admits, enough water to the distributing head I2 to completely cover or wet the surface of the coil 02 immediately below that portion of the head 12 to which water is delivered. Any greater opening of the valve will merely increase the amount of water which flows over that portion of the heater coil 62 without increasing the amount of wetted surface thereof. Inasmuch as, the rate of humidification is dependent upon the amount of wetted surface, it will be seen that the provision of separately controllable distributors for different portions of the surface of the coil 02 provides a reliable means for varying the rate of humidification of the air passing over the coil 62. The drip pan 56 collects the surplus water delivered from the distributinghead I2 and delivers it to the drain during winter operation, while during summer operation, the cooling coil 60 collects water of condensation from the air being cooled thereby which is also collected in the drip pan 56 and delivered to the drain.

While the form of embodiment of the present invention as herein disclosed constitutes a preferred form, it is to to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. Self-contained air conditioning apparatus comprising in combination, a liquefying unit, means forming an insulated compartment there for, a refrigerant evaporator connected to said liquefying unit, means forming an air duct en'- closing said evaporator and having an outlet communicating with a space to be air conditioned, an inlet communicating with said space, and a second inlet communicating with a fresh air supply, means for circulating air through said duct, heating means in said duct, means for varying the ratio between the quantities of air withdrawn through said inlets, and sectional sprays for supplying moisture to said heating means.

2. In combination, a refrigerant liquefying unit, a refrigerant evaporator in refrigerant flow relationship with said liquefying unit, means forming an air duct enclosing. said evaporator and having an outlet communicating with a space to be air conditioned, an inlet communicating with said space, a second inlet communicating with a fresh air supply, means for circulating air through said duct, heating means in said duct, means for varying the ratio between the quantities of air drawn through said inlets, and sectional sprays for supplying moisture to said heating means. i

3. In combination, a refrigerant liquefying.

unit, a refrigerant evaporator in refrigerant flow relationship with said liquefying unit, means forming an air duct enclosing said evaporator and having an outlet communicating with a space to be air conditioned, an inlet communicating with said space, a second inlet communicating with a fresh air supply, means for circulating air through said duct, heating means in said duct, means for varying the ratio between the quantities of air drawn through said inlets,

sectional sprays for supplying moisture to said' heating means, a solenoid valve between the lique'fying unit and the evaporator, and temperature responsive means for operating said valve.

NELSON J. SMITH. 

